Electric vehicles are about to form a widespread alternative to vehicles provided with internal combustion engines. The powertrain of an electric vehicle differs from that of a conventional vehicle mainly in that, instead of an internal combustion engine and a gearbox, the electric vehicle is equipped with one or more electric motors operatively connected to the driving wheels of the vehicle and, commonly, a battery pack for storage of electric energy.
This disclosure is concerned with electric motors supported by the vehicle frame structure, not with in-wheel motors incorporated into the hub of a driving wheel, for example.
The electric powertrain provides for a number of possibilities and challenges with regard to the design of the vehicle body frame structure for electric vehicles. An example of an issue is how to arrange an electric motor for driving of the front wheels of a passenger car, i.e., how to arrange the electric motor in a front portion of the car in what conventionally is referred to as the engine bay.
JP2012041009 discloses an arrangement for supporting an electric motor at the rear of a vehicle, wherein a motor supporting member is connected to left and right side frames and to a rear cross member. An arrangement of this type may work well for a rear portion of a vehicle, but in the front portion the situation is different, primarily because the frame structure in the front portion for safety reasons is designed very differently as compared to the rear portion. For instance, to absorb collision energy in case of a frontal collision, the side members are typically configured to deform by bending, buckling, etc. The arrangement of JP2012041009 is not adapted to deformation of side members or to handling of frontal collision energy.
Conventional arrangements for supporting an internal combustion engine in the engine bay are adapted to frontal crash situations, for instance by using engine mounts that break and detach the engine from the frame structure side members in the event of a crash. Electric motors, however, are generally much smaller than the conventional engines, so the same type of engine mounts cannot be used. Possibly, very large breakable engine/motor mounts could be developed and used, but this would lead to a complex and costly design.
There is a need for solutions regarding how to arrange the electric motor in an electric vehicle, in particular how to arrange the motor in a front portion of a passenger car.